Fused aromatic derivative and organic electroluminescence device using the same

ABSTRACT

A fused aromatic derivative shown by the following formula (1): 
                         
wherein R a  and R b  are independently a hydrogen atom or a substituent, p is an integer of 1 to 8 and q is an integer of 1 to 11, and when p and q are two or more, R a s and R b s may be independently the same or different, and adjacent substituents R a s may form a ring, L 1  is a single bond or a substituted or unsubstituted divalent linking group, and Ar 1  is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms, provided that when L 1  is a single bond and at least one of R a s is not a hydrogen atom, Ar 1  is not a triphenylenyl group, and provided that substituents of L 1  and Ar 1 , and R a  and R b  contain no amino group.

This application is a continuation of U.S. patent application Ser. No.12/743,815, filed Jul. 26, 2010, which is the National Phase ofInternational Patent Application No. PCT/JP2008/070882, filed Nov. 17,2008, which claims priority from Japanese Patent Application No.2007-301837, filed Nov. 21, 2007. The contents of these applications arehereby incorporated by reference in their entirety.

TECHNICAL FIELD

The invention relates to a novel fused aromatic derivative which isuseful as a material for an organic electroluminescence device, and anorganic electroluminescence device using the same.

BACKGROUND ART

An organic electroluminescence device (hereinafter the term“electroluminescence” is often abbreviated as “EL”) is a self-emissiondevice utilizing the principle that an emission material emits light bythe recombination energy of holes injected from an anode and electronsinjected from a cathode when an electric field is impressed.

An organic EL device has made a remarkable progress. In addition, sincean organic EL device has characteristics such as low voltage driving,high luminance, variety in emission wavelength, high response andcapability of fabricating a thin and lightweight emitting device, itsapplication to a wide range of fields is expected.

Emission materials used in an organic EL device have conventionally beenstudied actively since they influence largely the color of light emittedby a device or on emission life.

As the emission material, a chelate complex such astris(8-quinolinolato)aluminum complex, a coumarin derivative, atetraphenylbutadiene derivative, a bisstyrylarylene derivative and anoxadiazole derivative are known. By using such emission materials,emission in a visible range from blue to red can be obtained.

Use of a phosphorescent compound as an emission material for utilizingtriplet energy for emission has been studied. For example, it is knownthat an organic EL device using an iridium complex as an emissionmaterial exhibits a high luminous efficiency.

An organic EL device using polyphenylene vinylene (PPV) as a conjugatedpolymer is known. In this device, PPV is applied and formed into asingle film and this device is confirmed to emit light.

In Patent Document 1, an anthracene derivative is used as a material foran organic EL device.

In Patent Document 2, a compound having a triphenyl group is used as amaterial for an organic EL device.

In patent Document 3, an aminoanthryl derivative is used as a materialfor an organic EL device.

-   [Patent Document 1] JP-A-2004-59535-   [Patent Document 2] JP-A-2004-139957-   [Patent Document 3] JP-A-2006-151844

An object of the invention is to provide an organic material which issuitable for use as a material for an organic EL device.

DISCLOSURE OF THE INVENTION

The inventor(s) have found that a specific fused aromatic derivativehaving an anthracene structure and a triphenylene structure is effectivefor prolonging the lifetime, increasing the efficiency and lowering thevoltage of an organic EL device. The invention has been made on thisfinding.

According to the invention, the following fused aromatic derivative orthe like can be provided.

1. A fused aromatic derivative shown by the following formula (1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent,

p is an integer of 1 to 8, and q is an integer of 1 to 11, when p or qis 2 or more, R_(a)s or R_(b)s may be independently the same ordifferent, and adjacent substituents R_(a)s may form a ring,

L₁ is a single bond, or a substituted or unsubstituted divalent linkinggroup, and

Ar₁ is a substituted or unsubstituted aryl group having 6 to 50 carbonatoms that form a ring (hereinafter referred to as “ring carbon atoms”)or a substituted or unsubstituted heteroaryl group having 5 to 50 atomsthat form a ring (hereinafter referred to as “ring atoms”),

provided that when the triphenylene group bonds to the 9th or 10thposition of the anthracene skeleton, L₁ is a single bond and at leastone of R_(a)s is not a hydrogen, Ar₁ is not a triphenylenyl group, and

provided that substituents of L₁ and Ar₁ and R_(a) and R_(b) contain noamino group.

2. The fused aromatic derivative according to claim 1, which is shown bythe following formula (1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent,

p is an integer of 1 to 8, and q is an integer of 1 to 11, when p or qis two or more, R_(a)s or R_(b)s may be independently the same ordifferent, and adjacent substituents R_(a)s may form a ring,

L₁ is a single bond or a substituted or unsubstituted divalent linkinggroup, and

Ar₁ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms,

provided that when L₁ is a single bond and at least one of R_(a)s is nota hydrogen atom, Ar₁ is not a triphenylenyl group, and

provided that substituents of L₁ and Ar₁ and R_(a) and R_(b) contain noamino group.

3. The fused aromatic derivative according to claim 1 or 2, which isshown by the following formula (2):

wherein R_(a), R_(b), p and q are the same as in the formula (1), and

Ar₂ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms,

provided that when at least one of R_(a)s is not a hydrogen atom, Ar₂ isnot a triphenylenyl group.

4. The fused aromatic derivative according to claim 3, wherein in theformula (2), Ar₂ is a substituted or unsubstituted fused aromatic ringhaving 10 to 20 ring carbon atoms.

5. The fused aromatic derivative according to claim 1 or 2, which isshown by the following formula (3):

wherein R_(a), R_(b), p and q are the same as in the formula (1),

R_(c) is a hydrogen atom or substituent, and

r is an integer of 1 to 4, and when r is two or more, R_(c)s may be thesame or different, and

Ar₃ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms.

6. The fused aromatic derivative according to claim 5, wherein in theformula (3), Ar₃ is a substituted or unsubstituted fused aromatic ringhaving 10 to 20 ring carbon atoms.

7. The fused aromatic derivative according to claim 1 or 2, which isshown by the following formula (4):

wherein R_(a), R_(b), p and q are the same as in the formula (1),

R_(c) and R_(d) are independently a hydrogen atom or a substituent,

r and s are independently an integer of 1 to 4, and when r or s is twoor more, R_(c)s or R_(d)s are independently the same or different, and

Ar₄ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms.

8. The fused aromatic derivative according to claim 7, wherein in theformula (4), Ar₄ is a substituted or unsubstituted fused aromatic ringhaving 10 to 20 ring carbon atoms.

9. The fused aromatic derivative according to claim 1 or 2, which isshown by the following formula (5):

wherein R_(a), R_(b), p and q are the same as in the formula (1),

R_(d) is a hydrogen atom or a substituent,

s is an integer of 1 to 4, and when s is two or more, R_(d)s may be thesame or different, and

Ar₅ is a substituted or unsubstituted fused aromatic group having 10 to50 ring carbon atoms.

10. The fused aromatic derivative according to claim 9, wherein in theformula (5), Ar₅ is a substituted or unsubstituted naphthyl group.

11. A material for an organic electroluminescence device comprising thefused aromatic derivative according to any one of claims 1 to 10.

12. The material for an organic electroluminescence derivative accordingto claim 11, which is an emitting material.

13. An organic electroluminescence device comprising:

an anode, a cathode, and

one or more organic thin film layers comprising an emitting layerbetween the anode and the cathode,

wherein at least one of the organic thin film layers comprises the fusedaromatic derivative according to any one of claims 1 to 10.

14. The organic electroluminescence device according to claim 13,wherein the emitting layer comprises the fused aromatic derivative.

15. The organic electroluminescence device according to claim 14,wherein the emitting layer comprises the fused aromatic derivative as ahost material.

16. The organic electroluminescence device according to any one ofclaims 13 to 15, wherein the emitting layer further comprises at leastone of a fluorescent dopant and a phosphorescent dopant.

17. The organic electroluminescence device according to claim 16,wherein the fluorescent dopant is an arylamine compound.

18. The organic electroluminescence device according to claim 16,wherein the fluorescent dopant is a styrylamine compound.

According to the invention, it is possible to provide a fused aromaticderivative suitable as a material for an organic EL device.

The organic EL device using the fused aromatic derivative of theinvention has a long lifetime and a high efficiency, and is capable ofbeing driven at a low voltage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. is a schematic cross-sectional view of the organic EL deviceaccording to one embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the fused aromatic ring derivative of the invention will beexplained below concretely.

The fused aromatic ring derivative of the invention is a compound shownby the following formula (1):

in the formula (1),

R_(a) and R_(b) are independently a hydrogen atom or a substituent,

p is an integer of 1 to 8 and q is an integer of 1 to 11, when p or q istwo or more, R_(a)s or R_(b)s may be independently the same ordifferent, and adjacent substituents R_(a)s may form a ring,

L₁ is a single bond or a substituted or unsubstituted divalent linkinggroup, and

Ar₁ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms,

provided that when the triphenylene group bonds to the 9th or 10thposition of the anthracene skeleton, L₁ is a single bond and at leastone of R_(a)s is not a hydrogen atom, Ar₁ is not a triphenylenyl group,and

provided that substituents of L₁ and Ar₁, and R_(a) and R_(b) contain noamino group.

The fused aromatic derivative of the invention is preferably a compoundshown by the following formula (1):

in the formula (1),

R_(a) and R_(b) are independently a hydrogen atom or a substituent,

p is an integer of 1 to 8 and q is an integer of 1 to 11, and when p orq is two or more, R_(a)s or R_(b)s may be independently the same ordifferent and further adjacent substituents R_(a)s may form a ring,

L₁ is a single bond or a substituted or unsubstituted divalent linkinggroup, and

Ar₁ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms,

provided that when L₁ is a single bond and at least one of R_(a)s is nota hydrogen atom, Ar₁ is not a triphenylenyl group, and

provided that substituents of L₁ and Ar₁, and R_(a) and R_(b) contain noamino group.

In the formula (1), L₁ can bond to any position of 10 bonding positionswhich the anthracene ring has and to any position of 12 bondingpositions which the triphenylene ring has.

In the same manner, R_(a), R_(b) and Ar₁ can bond to any position otherthan the bonding positions of L1.

Examples of the substituent shown by R_(a) and R_(b) include an alkylgroup (one having preferably 1 to 20, more preferably 1 to 12 andparticularly preferably 1 to 8 carbon atoms, the specific examples ofwhich include methyl, ethyl, isopropyl, t-butyl, n-octyl, n-decyl,n-hexadecyl, cyclopropyl, cyclopentyl and cyclohexyl), an alkenyl group(one having preferably 2 to 20, more preferably 2 to 12 and particularlypreferably 2 to 8 carbon atoms, the specific examples of which includevinyl, allyl, 2-butenyl and 3-pentenyl), an alkynyl group (one havingpreferably 2 to 20, more preferably 2 to 12 and particularly preferably2 to 8 carbon atoms, the specific examples of which include propynyl and3-pentynyl), a substituted or unsubstituted aryl group (one havingpreferably 6 to 60, more preferably 6 to 30 and particularly preferably6 to 14 carbon atoms, the specific examples of which include phenyl,naphthyl, anthryl, and phenanthryl, examples of substituents of whichinclude an aryl group (one having preferably 6 to 20 and particularlypreferably 6 to 14 carbon atoms, the specific examples of which includephenyl, naphtyl and phenanthryl) and a heterocyclic group (one havingpreferably 1 to 30 and more preferably 1 to 12 carbon atoms, forexample, imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl,morpholino, benzoxazolyl, benzimidazolyl, benzothiazolyl, carbazolyl,benzofuranyl, dibenzofuranyl, benzothiophenyl and dibenzothiophenyl)),an aryloxy group (one having preferably 6 to 20, more preferably 6 to 16and particularly preferably 6 to 12 carbon atoms, the specific examplesof which include phenyloxy and 2-naphthyloxy), an acyl group (one havingpreferably 1 to 20, more preferably 1 to 16 and particularly preferably1 to 12 carbon atoms, the specific examples of which include acetyl,benzoyl, formyl and pivaloyl), an alkoxycarbonyl group (one havingpreferably 2 to 20, more preferably 2 to 16 and particularly preferably2 to 12 carbon atoms, the specific examples of which includemethoxycarbonyl and ethoxycarbonyl), an aryloxycarbonyl group (onehaving preferably 7 to 20, more preferably 7 to 16 and particularlypreferably 7 to 10 carbon atoms, the specific examples of which includephenyloxycarbonyl), an acyloxy group (one having preferably 2 to 20,more preferably 2 to 16 and particularly preferably 2 to 10 carbonatoms, the specific examples of which include acetoxy and benzoyloxy),an acylamino group (one having preferably 2 to 20, more preferably 2 to16 and particularly preferably 2 to 10 carbon atoms, the specificexamples of which include acetylamino and benzoylamino), analkoxycarbonylamino group (one having preferably 2 to 20, morepreferably 2 to 16 and particularly preferably 2 to 12 carbon atoms, thespecific examples of which include methoxycarbonylamino), anaryloxycarbonylamino group (one having preferably 7 to 20, morepreferably 7 to 16 and particularly preferably 7 to 12 carbon atoms, thespecific examples of which include phenyloxycarbonylamino), asubstituted or unsubstituted sulfonylamino group (one having preferably1 to 20, more preferably 1 to 16 and particularly preferably 1 to 12carbon atoms, the specific examples of which includemethanesulfonylamino and benzenesulfonylamino), a substituted orunsubstituted sulfamoyl group (one having preferably 0 to 20, morepreferably 0 to 16 and particularly preferably 0 to 12 carbon atoms, thespecific examples of which include sulfamoyl, methylsulfamoyl,dimethylsulfamoyl and phenylsulfamoyl), a substituted or unsubstitutedcarbamoyl group (one having preferably 1 to 20, more preferably 1 to 16and particularly preferably 1 to 12 carbon atoms, the specific examplesof which include carbamoyl, methylcarbamoyl, diethylcarbamoyl andphenylcarbamoyl), an alkylthio group (one having preferably 1 to 20,more preferably 1 to 16 and particularly preferably 1 to 12 carbonatoms, the specific examples of which include methylthio and ethylthio),an arylthio group (one having preferably 6 to 20, more preferably 6 to16 and particularly preferably 6 to 12 carbon atoms, the specificexamples of which include phenylthio), a substituted or unsubstitutedsulfonyl group (one having preferably 1 to 20, more preferably 1 to 16and particularly preferably 1 to 12 carbon atoms, the specific examplesof which include mesyl and tosyl), a substituted or unsubstitutedsulfinyl group (one having preferably 1 to 20, more preferably 1 to 16and particularly preferably 1 to 12 carbon atoms, the specific examplesof which include methanesulfinyl and benezenesulfinyl), a substituted orunsubstituted ureido group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include ureido, methylureido andphenylureido), a substituted or unsubstituted phosphoric amide group(one having preferably 1 to 20, more preferably 1 to 16 and particularlypreferably 1 to 12 carbon atoms, the specific examples of which includediethylphosphoric amide and phenylphosphoric amide), a hydroxyl group, amercapto group, a halogen atom (for example, a fluorine atom, a chlorineatom, a bromine atom and an iodine atom), a cyano group, a sulfo group,a carboxy group, a nitro group, a hydroxamic acid group, a sulfinogroup, a hydrazino group, an imino group, a heterocyclic group (onehaving preferably 1 to 30 and more preferably 1 to 12 carbon atoms andcontaining, as the hetero atom, a nitrogen atom, an oxygen atom and asulfur atom, for example, the specific examples of which includeimidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino,benzoxazolyl, benzimidazolyl, benzothiazolyl, carbazolyl, benzofuranyl,dibenzofuranyl, benzothiophenyl and dibenzothiophenyl), and a silylgroup (one having preferably 3 to 40, more preferably 3 to 30 andparticularly preferably 3 to 24 carbon atoms, the examples of whichinclude trimethylsilyl and triphenylsilyl). These substituents may befurther substituted.

Among the above groups, an alkyl group, an alkenyl group, an aryl group,a carbazolyl group, a dibenzofuranyl group, a dibenzothiopheynl group, acarbazolylaryl group, a dibenzofuranylaryl group and adibenzothiophenylaryl group are preferable.

Examples of the substituted or unsubstituted divalent linking groupindicated by L₁ include a substituted or unsubstituted arylene having 6to 50 ring carbon atoms. Specifically, divalent groups can be mentionedwhich correspond to groups obtained by eliminating one hydrogen atomfrom the following aryl groups:

a phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group,2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthrylgroup, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group,1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group,1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group,3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group,p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group,m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolylgroup, p-tolyl group, p-t-butylphenyl group, p-(2-phenylpropyl)phenylgroup, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group,4-methyl-1-anthryl group, 4′-methylbiphenylyl group and4″-t-butyl-p-terphenyl-4-yl group.

Among the above groups, a substituted or unsubstituted phenylene group,particularly a phenylene group is preferable.

L₁ may be a divalent group formed by combination of two or more of theabove-mentioned arylene groups or single bonds.

As examples of the substituted or unsubstituted aryl group having 6 to50 ring carbon atoms indicated by Ar₁, a phenyl group, 1-naphthyl group,2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group,1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group,4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group,2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenylgroup, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group,4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group,p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group,m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group,p-t-butylphenyl group, p-(2-phenylpropyl)phenyl group,3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthrylgroup, 4′-methylbiphenylyl group, 4″-t-butyl-p-terphenyl-4-yl group andthe like can be given.

Ar₁ may be an aryl group having 6 to 50 ring carbon atoms which issubstituted by a substituted or unsubstituted aryl group having 6 to 50ring carbon atoms or a substituted or unsubstituted heteroaryl grouphaving 5 to 50 ring atoms as mentioned below.

Examples of those groups include aryl-substituted phenyl groups such asa naphthyl-substituted phenyl group and a phenanthryl-substituted phenylgroup, aryl-substituted naphthyl groups such as a phenyl-substitutednaphthyl group and a binaphthyl group, and a dibenzofuranyl-substitutedphenyl group.

Of these, an aryl-substituted phenyl group shown by the followingformula is preferable.

wherein

R_(c) is a hydrogen atom or a substituent,

r is an integer of 1 to 4, and when r is two or more, R_(c)s may be thesame or different, and

Ar₃ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms.

Examples of a substituted or unsubstituted aryl group having 6 to 50ring carbon atoms which is indicated by Ar₃ are the same as the examplesfor Ar₁ in the above-mentioned formula (1). Examples of substituentswhich is indicated by R_(c) are the same as the examples for R_(a) inthe above-mentioned formula (1).

Examples of the substituted or unsubstituted heteroaryl group having 5to 50 ring atoms indicated by Ar₁ include a 1-pyrrolyl group, 2-pyrrolylgroup, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinylgroup, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolylgroup, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolylgroup, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group,4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolylgroup, 2-furyl group, 3-furyl group, 2-benzofuranyl group,3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group,6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group,3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranylgroup, 6-isobenzofuranyl group, 7-isobenzofuranyl group,1-dibenzofuranyl group, 2-dibenzofuranyl group, 3-dibenzofuranyl group,4-dibenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group,1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinylgroup, 4-phenanthridinyl group, 6-phenanthridinyl group,7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinylgroup, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group,3-acridinyl group, 4-acridinyl group, 9-acridinyl group,1,7-phenanthrolin-2-yl group, 1,7-phenanthrolin-3-yl group,1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group,1,7-phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group,1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group,1,8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group,1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group,1,8-phenanthrolin-6-yl group, 1,8-phenanthrolin-7-yl group,1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group,1,9-phenanthrolin-2-yl group, 1,9-phenanthrolin-3-yl group,1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group,1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group,1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group,1,10-phenanthrolin-2-yl group, 1,10-phenanthrolin-3-yl group,1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl group,2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group,2,9-phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group,2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group,2,9-phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group,2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group,2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group,2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl group,2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group,2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group,2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5-yl group,2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group,2,7-phenanthrolin-9-yl group, 2,7-phenanthrolin-10-yl group,1-phenazinyl group, 2-phenazinyl group, 1-phenothiadinyl group,2-phenothiadinyl group, 3-phenothiadinyl group, 4-phenothiadinyl group,10-phenothiadinyl group, 1-phenoxadinyl group, 2-phenoxadinyl group,3-phenoxadinyl group, 4-phenoxadinyl group, 10-phenoxadinyl group,2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolylgroup, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group,3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group,2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group,3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group,3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group,2-t-butylpyrrol-4-yl group, 3-(2-phenylpropyl)pyrrol-1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group, and4-t-butyl-3-indolyl group.

p is an integer of 1 to 8 and q is an integer of 1 to 11. When p is twoor more, plural R_(a)s may be the same or different. In the same manner,when q is two or more, R_(b)s may be the same or different.

Adjacent R_(a)s may form a saturated or unsaturated ring.

In the formula (1), a compound where L₁ is a single bond, at least oneof R_(a)s is not a hydrogen atom and Ar₁ is a triphenylenyl group is notincluded in the fused aromatic derivative of the invention. Substituentsof L₁ and Ar₁, and R_(a) and R_(b) contain no amino group.

The fused aromatic derivative of the invention is preferably a compoundshown by the following formula (2):

in the formula (2),

R_(a), R_(b), p and q are the same as in the formula (1), and

Ar₂ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms,

provided that when at least one of R_(a)s is not a hydrogen atom, Ar₂ isnot triphenylenyl.

Examples of the substituted or unsubstituted aryl group having 6 to 50ring carbon atoms which is indicated by Ar₂ are the same as the examplesof Ar₁ in the above-mentioned formula (1).

In the formula (2), a compound where Ar₂ is a substituted orunsubstituted fused aromatic ring having 10 to 20 ring carbon atoms isparticularly preferable. Specific examples thereof include a 1-naphthylgroup, a 2-naphthyl group, a 9-anthracenyl group, a 2-phenanthryl groupand a 3-phenanthryl group.

Alternatively, a compound shown by the following formula (3) ispreferable.

In the formula (3), R_(a), R_(b), p and q are the same as in the aboveformula (1),

R_(c) is a hydrogen atom or a substituent,

r is an integer of 1 to 4, and when r is two or more, R_(c)s may be thesame or different, and

Ar₃ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms.

Examples of the substituted or unsubstituted aryl group having 6 to 50ring carbon atoms and the substituted or unsubstituted heteroaryl grouphaving 5 to 50 ring atoms which is indicated by Ar₃ are the same as theexamples of Ar₁ in the above-mentioned formula (1). Examples of thesubstituent indicated by R_(c) are the same as the examples of R_(a) inthe above-mentioned formula (1).

Also, in the formula (3), a compound where Ar₃ is a substituted orunsubstituted fused aromatic ring having 10 to 20 ring carbon atoms isparticularly preferable. Specific examples thereof are the same as inthe formula (2).

Alternatively, a compound shown by the following formula (4) ispreferable.

In the formula (4),

R_(a), R_(b), p and q are the same as in the above formula (1),

R_(c) and R_(d) are independently a hydrogen atom or a substituent,

r and s are independently an integer of 1 to 4, and when r or s is twoor more, R_(c)s or R_(d)s may be independently the same or different,and

Ar₄ is a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms.

Examples of the substituted or unsubstituted aryl group having 6 to 50ring carbon atoms and the substituted or unsubstituted heteroaryl grouphaving 5 to 50 ring atoms which is indicated by Ar₄ are the same as theexamples of Ar₁ in the above-mentioned formula (1). Examples of thesubstituents which are indicated by R_(c) and R_(d) are the same as theexamples of R_(a) in the above-mentioned formula (1).

Also, in the formula (4), a compound where Ar₄ is a substituted orunsubstituted fused aromatic ring having 10 to 20 ring carbon atoms isparticularly preferable. Specific examples thereof are the same as inthe formula (2).

Alternatively, a compound shown by the following formula (5):

in the formula (5),

R_(a), R_(b), p and q are the same as in the formula (1),

R_(d) is a hydrogen atom or a substituent,

s is an integer of 1 to 4, and when s is two or more, R_(d)s may be thesame or different, and

Ar₅ is a substituted or unsubstituted fused aromatic group having 10 to50 ring carbon atoms.

Examples of the substituents which is indicated by R_(d) are the same asthe examples of R_(a) in the above-mentioned formula (1).

Examples of the substituted or unsubstituted fused aromatic group having10 to 50 ring carbon atoms which is indicated by Ar₅ include a1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthrylgroup, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group,a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a1-naphthacenyl group, a 2-naphthacenyl group, a 9-naphthacenyl group, a1-pyrenyl group, a 2-prenyl group, a 4-pyrenyl group, a3-methyl-2-naphthyl group, a 4-methyl-1-naphthyl group and a4-methyl-1-anthryl group.

As Ar₅, a substituted or unsubstituted naphthyl group is particularlypreferable. As the substituent, the same groups as R_(a) in the formula(1) may be mentioned. Among them, a 1-naphthyl group and a 2-naphthylgroup are preferable.

Examples of the fused aromatic ring derivative of the invention will beshown below:

The fused aromatic derivative of the invention can be synthesized bycyclization of ortho-terphenyl derivative. The synthesis will bespecifically explained in examples.

The fused aromatic derivative of the invention (hereinafter oftenreferred to as the compound of the invention) is suitably used for amaterial for an organic EL device, particularly as the emittingmaterial. The material for an organic EL device of the inventioncomprises the fused aromatic derivative, or consists essentially of thefused aromatic derivative of the invention.

The organic EL device of the invention comprises an anode, a cathode andone or more organic thin layers comprising an emitting layer between theanode and the cathode, and at least one of the organic thin layerscomprise the above-mentioned compound of the invention.

Representative configurations of the organic EL device of the inventioncan be given below.

(1) Anode/emitting layer/cathode

(2) Anode/hole-injecting layer/emitting layer/cathode

(3) Anode/emitting layer/electron-injecting layer/cathode

(4) Anode/hole-injecting layer/emitting layer/electron-injectinglayer/cathode

(5) Anode/organic semiconductor layer/emitting layer/cathode

(6) Anode/organic semiconductor layer/electron-barrier layer/emittinglayer/cathode

(7) Anode/organic semiconductor layer/emitting layer/adhesion-improvinglayer/cathode

(8) Anode/hole-injecting layer/hole-transporting layer/emittinglayer/electron-injecting layer/cathode

(9) Anode/insulating layer/emitting layer/insulating layer/cathode

(10) Anode/inorganic semiconductor layer/insulating layer/emittinglayer/insulating layer/cathode

(11) Anode/organic semiconductor layer/insulating layer/emittinglayer/insulating layer/cathode

(12) Anode/insulating layer/hole-injecting layer/hole-transportinglayer/emitting layer/insulating layer/cathode

(13) Anode/insulating layer/hole-injecting layer/hole-transportinglayer/emitting layer/electron-injecting layer/cathode

The representative examples of the configuration of the organic ELdevice of the invention are, however, not limited to the above. Ofthese, the configuration (8) is preferable.

The configuration (8) is shown in FIG. This organic EL device comprisesan anode 10, a cathode 20, and a hole-injecting layer 30, ahole-transporting layer 32, an emitting layer 34 and anelectron-injecting layer 36 between the anode and the cathode. Thehole-injecting layer 30, the hole-transporting layer 32, the emittinglayer 34 and the electron-injecting layer 36 correspond to the pluralityof organic thin film layers. At least one of these organic thin filmlayers 30, 32, 34 and 36 comprises the compound of the invention.

In the organic EL device of the invention, although the compound of theinvention may be used in any of the above-mentioned organic thin filmlayers, it is preferred that the compound of the invention be used inthe emitting layer. In each of the organic thin film layers, thecompound of the invention may be used either singly or in mixture withother compounds. In the device of the invention, it is preferred thatthe emitting layer contain the compound of the invention as a hostmaterial and contain at least one of a fluorescent dopant and aphosphorescent dopant.

In the invention, it is preferred that the emitting layer consistessentially of the compound of the invention and the above-mentioneddopant.

The content of the compound of the invention in the organic thin filmlayers is preferably 30 to 100 mol %.

Each member of the organic EL device will be explained below.

The organic EL device is normally formed on a substrate. The substratesupports the organic EL device. It is preferable to use a smoothsubstrate. If light is outcoupled through the substrate, it is preferredthat the substrate be a transparent substrate with a transmission tovisible rays with a wavelength of 400 to 700 nm of 50% or more.

As such transparent substrate, a glass plate, a synthetic resin plate orthe like are preferably used. Examples of the glass plate include platesof soda-lime glass, barium/strontium-containing glass, lead glass,aluminosilicate glass, borosilicate glass, barium borosilicate glass,quartz, or the like. Examples of the synthetic resin plates includeplates of a polycarbonate resin, an acrylic resin, a polyethyleneterephthalate resin, a polyether sulfide resin, a polysulfone resin, orthe like.

It is effective that the anode injects holes to the hole-injectinglayer, the hole-transporting layer or the emitting layer and has a workfunction of 4.5 eV or more. Specific examples of the anode materialinclude indium tin oxide (ITO), a mixture of indium oxide and zinc oxide(IZO), a mixture of ITO and cerium oxide (ITCO), a mixture of IZO andcerium oxide (IZCO), a mixture of indium oxide and cerium oxide (ICO), amixture of zinc oxide and aluminum oxide (AZO), tin oxide (NESA), gold,silver, platinum and copper.

The anode can be formed from these electrode materials by a vapordeposition method, a sputtering method or the like.

In the case where emission from the emitting layer is outcoupled throughthe anode, the transmittance of the anode to the emission is preferablymore than 10%. The sheet resistance of the anode is preferably severalhundred Ω/□ or less. The film thickness of the anode, which variesdepending upon the material thereof, is usually from 10 nm to 1 μm,preferably from 10 to 200 nm.

The emitting layer has the following functions.

(i) Injection function: function of allowing injection of holes from theanode or hole-injecting layer and injection of electrons from thecathode or electron-injecting layer upon application of an electricfield

(ii) Transporting function: function of moving injected carriers(electrons and holes) due to the force of an electric field

(iii) Emission function: function of recombining electrons and holes toemit light

As the method of forming the emitting layer, a known method such asdeposition, spin coating, or an LB method may be applied. It ispreferable that the emitting layer be a molecular deposition film. Themolecular deposition film is a film formed by deposition of a materialcompound in a gas phase, or by solidification of a material compound inthe form of a solution or in a liquid phase. The molecular depositionfilm can be usually distinguished from a thin film (molecularaccumulation film) formed using the LB method by the difference inaggregation structure or higher order structure or the difference infunction due to the difference in structure.

The emitting layer may also be formed by dissolving a binder such as aresin and a material compound in a solvent to obtain a solution, andforming a thin film from the solution by spin coating or the like.

In the organic EL device of the invention, it is preferred that theemitting layer contain the emitting material of the invention as a hostand contain at least one of a phosphorescent dopant and a fluorescentdopant. An emitting layer containing these dopants may be stacked on anemitting layer containing the compound of the invention.

A phosphorescent dopant is a compound that can emit light from tripletexcitons. The dopant is not limited so long as it can emit light fromtriplet excitons, but it is preferably a metal complex containing atleast one metal selected from the group of Ir, Ru, Pd, Pt, Os and Re. Aporphyrin metal complex or an ortho-metalated metal complex ispreferable. The phosphorescent compounds can be used individually or asa combination of two or more kinds.

As a porphyrin metal complex, a porphyrin platinum complex ispreferable.

There are various ligands forming an ortho-metalated metal complex.Preferable ligands include compounds having a phenylpyridine skeleton, abipyridyl skeleton or a phenanthroline skeleton, 2-phenylpyridine,7,8-benzoquinoline, 2-(2-thienyl)pyridine, 2-(1-naphthyl)pyridine and2-phenylquinoline derivatives. These ligands may have a substituent, ifnecessary. Ligands to which fluorides, e.g. a trifluoromethyl group,being introduced as a substituent are particularly preferable as a bluedopant. As an auxiliary ligand, preferred are ligands other than theabove-mentioned ligands, such as acetylacetonate and picric acid may becontained.

Examples of such metal complexes include tris(2-phenylpiridine)iridium,tris(2-phenylpiridine)ruthenium, tris(2-phenylpiridine)palladium,bis(2-phenylpiridine)platinum, tris(2-phenylpiridine)osmium,tris(2-phenylpiridine)rhenium, octaethyl platinum porphyrin, octaphenylplatinum porphyrin, octaethyl palladium porphyrin and octaphenylpalladium porphyrin. However, not limited to the above, and anappropriate complex can be selected depending on the required emittingcolor, device performance and a host compound used.

The content of a phosphorescent dopant in an emitting layer is notlimited and can be properly selected according to purposes; for example,it is 0.1 to 70 mass %, preferably 1 to 30 mass %. When the content of aphosphorescent compound is less than 0.1 mass %, emission may be weakand the advantages thereof may not be sufficiently obtained. When thecontent exceeds 70 mass %, the phenomenon called concentration quenchingmay significantly proceed, thereby degrading the device performance.

As for the fluorescent dopant, it is preferable to select a compoundfrom amine-based compounds, aromatic compounds, chelate complexes suchas tris(8-quinolilate)aluminum complexes, coumarin derivatives,tetraphenylbutadiene derivatives, bisstyrylarylene derivatives,oxadiazole derivatives or the like, taking into consideration requiredemission colors. Of these, styrylamine compounds, styryldiaminecompounds, arylamine compounds and aryldiamine compounds are furtherpreferable. Fused polycyclic aromatic compounds which are not an aminecompound are also preferable. These fluorescent dopants may be usedsingly or in combination of two or more.

The content of a fluorescent dopant in the emitting layer is notparticularly limited and can be appropriately selected according topurposes; for example, it is 0.1 to 70 mass %, preferably 1 to 30 mass%.

As the styrylamine compound and the styryldiamine compound, those shownby the following formula (A) are preferable.

wherein Ar¹⁰¹ is a group with a valence of p corresponding to a phenylgroup, a naphthyl group, a biphenyl group, a terphenyl group, astilbenzyl group or a distyrylaryl group, Ar¹⁰² and Ar¹⁰³ areindependently an aromatic hydrocarbon group having 6 to 20 carbon atoms,Ar¹⁰¹, Ar¹⁰² and Ar¹⁰³ may be substituted, one of Ar¹⁰¹ to Ar¹⁰³ issubstituted by a styryl group, further preferably, at least one of Ar¹⁰²and Ar¹⁰³ is substituted by a styryl group, and p is an integer of 1 to4, preferably an integer of 1 to 2.

Here, as the aromatic hydrocarbon group having 6 to 20 carbon atoms, aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a terphenyl group or the like can be given.

As the arylamine compound and the aryldiamine compound, those shown bythe following formula (B) are preferable.

wherein A¹¹¹ is a substituted or unsubstituted aromatic group with avalence of q having 5 to 40 ring carbon atoms, Ar¹¹² and Ar¹¹³ areindependently a substituted or unsubstituted aryl group having 5 to 40ring carbon atoms, and q is an integer of 1 to 4, preferably an integerof 1 to 2.

Examples of the aryl group having 5 to 40 ring carbon atoms include aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a pyrenyl group, a coronyl group, a biphenyl group, a terphenyl group, apyrrolyl group, a furanyl group, a thiophenyl group, a benzothiophenylgroup, an oxadiazolyl group, a diphenylanthranyl group, an indolylgroup, a carbazolyl group, a pyridyl group, a benzoquinolyl group, afluoranthenyl group, an acenaphthofluoranthenyl group, a stilbene group,a perylenyl group, a chrysenyl group, a picenyl group, a triphenylenylgroup, a rubicenyl group, a benzanthracenyl group, a phenylanthranylgroup and a bisanthracenyl group. Preferred are a naphthyl group, ananthranyl group, chrysenyl group and a pyrenyl group.

As the Ar¹¹¹, the above-mentioned q-valent group is preferable. WhenAr¹¹¹ is a divalent group, groups shown by the following formulas (C)and (D) are preferable. A group shown by the formula (D) is morepreferable.

(in the formula (C), r is an integer of 1 to 3)

Preferred substituents for the above-mentioned aryl group include analkyl group having 1 to 6 carbon atoms (ethyl, methyl, i-propyl,n-propyl, s-butyl, t-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, orthe like); an alkoxy group having 1 to 6 carbon atoms (ethoxy, methoxy,i-propoxy, n-propoxy, s-buthoxy, t-buthoxy, penthoxy, hexyloxy,cyclopentoxy, cyclohexyloxy, or the like); an aryl group having 5 to 40ring carbon atoms; an amino group substituted with an aryl group having5 to 40 ring carbon atoms; an ester group with an aryl group having 5 to40 ring carbon atoms; an ester group with an alkyl group having 1 to 6carbon atoms; a cyano group; a nitro group; and a halogen atom.

The emitting layer may contain hole-transporting materials,electron-transporting materials and polymer binders, if necessary.

The thickness of an emitting layer is preferably from 5 to 50 nm, morepreferably from 7 to 50 nm and most preferably from 10 to 50 nm. When itis less than 5 nm, the formation of an emitting layer and the adjustmentof chromaticity may become difficult. When it exceeds 50 nm, the drivingvoltage may increase.

The hole-transporting layer and the hole-injecting layer are layerswhich help the injection of holes into the emitting layer so as totransport holes to an emitting region, and have a large hole mobilityand normally have such a small ionization energy as 5.5 eV or less. Asthe material for the hole-injecting layer and the hole-transportinglayer, a material which transports holes to the emitting layer at alower electrical field is preferable, and the hole mobility thereof ispreferably 10⁻⁴ cm²/V·second or more when an electric field of, e.g.,10⁴ to 10⁶ V/cm is applied.

There are no particular restrictions on the material for thehole-injecting layer and the hole-transporting layer. The material canbe arbitrarily selected from materials which have been widely used as ahole-transporting material of photoconductive materials and knownmaterials used in a hole-injecting layer and a hole-transporting layerof organic EL devices.

In the hole-injecting layer and the hole-transporting layer, an aromaticamine derivative shown by the following formula can be used, forexample.

wherein Ar²¹¹ to Ar²¹³ and Ar²²¹ to Ar²²³ are independently asubstituted or unsubstituted aryl group having 6 to 50 ring carbon atomsor a substituted or unsubstituted heteroaryl group having 5 to 50 ringatoms, Ar²⁰³ to Ar²⁰⁸ are independently a substituted or unsubstitutedarylene group having 6 to 50 ring carbon atoms or a substituted orunsubstituted heteroarylene group having 5 to 50 ring atoms, a to c andp to r are independently an integer of 0 to 3, and Ar²⁰³ and Ar²⁰⁴,Ar²⁰⁵ and Ar²⁰⁶, or Ar²⁰⁷ and Ar²⁰⁸ may be bonded to each other to forma saturated or unsaturated ring.

Examples of the substituted or unsubstituted aryl group having 6 to 50ring carbon atoms or the substituted or unsubstituted heteroaryl grouphaving 5 to 50 ring atoms are the same as the examples of Ar₁ in theabove-mentioned formula (1).

Further, the compound shown by the following formula can be used in thehole-injecting layer and the hole-transporting layer.

wherein Ar²³¹ to Ar²³⁴ are independently a substituted or unsubstitutedaryl group having 6 to 50 ring carbon atoms, or a substituted orunsubstituted heteroaryl group having 5 to 50 ring atoms, L is a linkinggroup, which is a single bond, a substituted or unsubstituted arylenegroup having 6 to 50 ring carbon atoms or a substituted or unsubstitutedheteroarylene group having 5 to 50 ring atoms, x is an integer of 0 to5, and Ar²³² and Ar²³³ may be bonded to each other to form a saturatedor unsaturated ring.

As specific examples of the substituted or unsubstituted aryl grouphaving 6 to 50 ring carbon atoms and substituted or unsubstitutedheteroaryl group having 5 to 50 ring atoms, the same as thoseexemplified for Ar₁ in the above-mentioned formula (1) can be given.

As specific examples of the material for the hole-injecting layer andthe hole-transporting layer, a triazole derivative, an oxadiazolederivative, an imidazole derivative, a polyarylalkane derivative, apyrazoline derivative, a pyrazolone derivative, a phenylenediaminederivative, an arylamine derivative, an amino-substituted chalkonederivative, an oxazole derivative, a styrylanthracene derivative, afluorenone derivative, a hydrazone derivative, a stilbene derivative, asilazane derivative, an aniline-based copolymer, and conductivehigh-molecular oligomers (in particular, a thiophene oligomer) can begiven.

As the material for the hole-injecting layer and the hole-transportinglayer, although the above-mentioned materials can be used, it ispreferable to use a porphyrin compound, an aromatic tertiary aminecompound and a styrylamine compound. It is particularly preferable touse an aromatic tertiary amine compound.

It is preferable to use a compound having two fused aromatic rings inthe molecule thereof, for example,4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (abbreviated by NPD,hereinafter), and4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine(abbreviated by MTDATA, hereinafter) wherein three triphenylamine unitsare linked in a star-burst form.

In addition to the above, a nitrogen-containing heterocyclic derivativeshown by the following formula can also be used.

wherein R²⁰¹ to R²⁰⁶ are independently a substituted or unsubstitutedalkyl group, a substituted or unsubstituted aryl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted heterocyclicgroup, and R²⁰¹ and R²⁰², R²⁰³ and R²⁰⁴, R²⁰⁵ and R²⁰⁶, R²⁰¹ and R²⁰⁶,R²⁰² and R²⁰³, or R²⁰⁴ and R²⁰⁵ may form a fused ring.

Further, the following compound can also be used.

wherein R²¹¹ to R²¹⁶ are substituents; preferably they are independentlyan electron-attracting group such as a cyano group, a nitro group, asulfonyl group, a carbonyl group, a trifluoromethyl group and a halogen.

Further, an inorganic compound such as p-type Si and p-type SiC can alsobe used as a material for the hole-injecting layer and thehole-transporting layer.

The hole-injecting layer and the hole-transporting layer can be formedfrom the above-mentioned compounds by a known method such as vaporvacuum deposition, spin coating, casting or LB technique. The filmthickness of the hole-injecting layer and the hole-transporting layer isnot particularly limited, and is usually from 5 nm to 5 μm. Thehole-injecting layer and the hole-transporting layer may be a singlelayer made of one or two or more of the above-mentioned materials, ormay be of a structure in which hole-injecting layers andhole-transporting layers made of different compounds are stacked.

The organic semiconductor layer is a layer for helping the injection ofholes or electrons into the emitting layer, and is preferably a layerhaving an electric conductivity of 10⁻¹⁰ S/cm or more. As the materialof such an organic semiconductor layer, electroconductive oligomers suchas thiophene-containing oligomers or arylamine-containing oligomers andelectroconductive dendrimers such as arylamine-containing dendrimers maybe used.

The electron-injecting layer and the electron-transporting layer arelayers which assist injection of electrons into the emitting layer andtransport electrons to the emitting region, and exhibit a high electronmobility. The adhesion-improving layer is a kind of theelectron-injecting layer which is made of a material exhibitingparticularly good adhesion to the cathode.

The thickness of the electron-transporting layer is arbitrarily selectedin the range of 5 nm to 5 μm. When the electron-transporting layer has athick thickness, it is preferable that the electron mobility be 10⁻⁶cm²/Vs or more at an applied electric field of 10⁴ to 10⁶ V/cm in orderto prevent an increase in voltage.

The material used in the electron-injecting layer and theelectron-transporting layer is preferably a metal complex of8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative.Specific examples of the metal complex of 8-hydroxyquinoline orderivative thereof include metal chelate oxynoid compounds containing achelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline), e.g.tris(8-quinolinolato)aluminum.

As examples of the oxadiazole derivative, an electron-transportingcompound shown by the following formula can be given.

wherein Ar³⁰¹, Ar³⁰², Ar³⁰³, Ar³⁰⁵, Ar³⁰⁶ and Ar³⁰⁹ are independently asubstituted or unsubstituted aryl group, and Ar³⁰⁴, Ar³⁰⁷ and Ar³⁰⁸ areindependently a substituted or unsubstituted arylene group.

As examples of the aryl group, a phenyl group, a biphenyl group, ananthranyl group, a perylenyl group, and a pyrenyl group can be given. Asexamples of the arylene group, a phenylene group, a naphthylene group, abiphenylene group, an anthranylene group, a perylenylene group, apyrenylene group, and the like can be given. As the substituent, analkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10carbon atoms, a cyano group, and the like can be given. Theelectron-transporting compound is preferably one from which a thin filmcan be formed.

The following compounds can be given as specific examples of theelectron-transporting compound.

(Me is methyl and tBu is t-butyl.)

Furthermore, as materials used for the electron-injecting layer andelectron-transporting layer, the compounds represented by the followingformulas (E) to (J) may be used.

Nitrogen-containing heterocyclic derivatives shown by the formulas (E)and (F):wherein Ar³¹¹ to Ar³¹³ are independently a nitrogen atom or a carbonatom,

Ar³¹¹ is a substituted or unsubstituted aryl group having 6 to 60 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 3to 60 ring atoms, Ar^(311′) is an arylene group having 6 to 60 ringcarbon atoms or a substituted or unsubstituted heteroarylene grouphaving 3 to 60 ring atoms, and Ar³¹² is a hydrogen atom, a substitutedor unsubstituted aryl group having 6 to 60 ring carbon atoms, asubstituted or unsubstituted heteroaryl group having 3 to 60 ring atoms,a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,or a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, provided that one of Ar³¹¹ and Ar³¹² is a substituted orunsubstituted fused ring group having 10 to 60 ring carbon atoms or asubstituted or unsubstituted monohetero fused ring group having 3 to 60ring atoms,

L³¹¹, L³¹² and L³¹³ are independently a single bond, a substituted orunsubstituted arylene group having 6 to 60 ring carbon atoms, asubstituted or unsubstituted heteroarylene group having 3 to 60 ringatoms, or a substituted or unsubstituted fluorenylene group,

R and R³¹¹ are independently a hydrogen atom, a substituted orunsubstituted aryl group having 6 to 60 ring carbon atoms, a substitutedor unsubstituted heteroaryl group having 3 to 60 ring atoms, asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms, ora substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,

n is an integer of 0 to 5, and

when n is two or more, plural Rs may be the same or different, andadjacent Rs may be bonded to each other to form a carbocyclic aliphaticring or a carbocyclic aromatic ring.HAr-L³¹⁴-Ar³²¹—Ar³²²  (G)Nitrogen-containing heterocyclic derivatives shown by the formula (G):wherein HAr is a nitrogen-containing heterocyclic ring having 3 to 40carbon atoms, which may have a substituent, L³¹⁴ is a single bond, anarylene group having 6 to 60 carbon atoms, which may have a substituent,an heteroarylene group having 3 to 60 atoms, which may have asubstituent, or a fluorenylene group which may have a substituent, Ar³²¹is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms,which may have a substituent, and Ar³²² is an aryl group having 6 to 60carbon atoms, which may have a substituent or a heteroaryl group having3 to 60 atoms, which may have a substituent.

Silacyclopentadiene derivatives shown by the formula (H) wherein X³⁰¹and Y³⁰¹ are independently a saturated or unsaturated hydrocarbon grouphaving 1 to 6 carbon atoms, an alkoxy group, an alkenyloxy group, analkynyloxy group, a hydroxyl group, a substituted or unsubstituted arylgroup, or a substituted or unsubstituted hetero ring, or X and Y arebonded to form a saturated or unsaturated ring, and R³⁰¹ to R³⁰⁴ areindependently hydrogen, halogen, an alkyl group, an alkoxy group, anaryloxy group, a perfluoroalkyl group, a perfluoroalkoxy group, an aminogroup, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, an azo group, an alkylcarbonyloxygroup, an arylcarbonyloxy group, an alkoxycarbonyloxy group, anaryloxycarbonyloxy group, a sulfinyl group, a sulfonyl group, a sulfanylgroup, a silyl group, a carbamoyl group, an aryl group, a heterocyclicgroup, an alkenyl group, an alkynyl group, a nitro group, a formylgroup, a nitroso group, a formyloxy group, an isocyano group, a cyanategroup, an isocyanate group, a thiocyanate group, an isothiocyanategroup, or a cyano group. These groups may be substituted and adjacentgroups may form a substituted or unsubstituted fused ring.

Borane derivatives shown by the formula (I) wherein R³²¹ to R³²⁸ andZ³²² are independently a hydrogen atom, a saturated or unsaturatedhydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group,a substituted amino group, a substituted boryl group, an alkoxy group,or an aryloxy group, X³⁰², Y³⁰², and Z³²¹ are independently a saturatedor unsaturated hydrocarbon group, an aromatic hydrocarbon group, aheterocyclic group, a substituted amino group, an alkoxy group, or anaryloxy group, Z³²¹ and Z³²² may be bonded to form a fused ring, and nis an integer of 1 to 3, provided that when n or (3-n) is two or more,R³²¹ to R³²⁸, X³⁰², Y³⁰², Z³²² and Z³²¹ may be the same or different,provided that compounds where n is 1, X³⁰², Y³⁰², and R³²² are methylgroups, and R³²⁸ is a hydrogen atom or a substituted boryl group, andcompounds where n is 3 and Z³²¹ is a methyl group are excluded.

Gallium complexes shown by the formula (J) wherein Q³⁰¹ and Q³⁰² areindependently ligands represented by the following formula (K) and L³¹⁵is a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heterocyclicgroup, —OR(R is a hydrogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup) or a ligand represented by —O—Ga-Q³⁰³(Q³⁰⁴) wherein Q³⁰³ and Q³⁰⁴are the same as Q³⁰¹ and Q³⁰².

wherein rings A³⁰¹ and A³⁰² are independently a 6-membered aryl ringstructure which may have a substituent and they are fused to each other.

The metal complexes have the strong nature of an n-type semiconductorand large ability of injecting electrons. Further, the energy generatedat the time of forming a complex is small so that a metal is thenstrongly bonded to ligands in the complex formed and the fluorescentquantum efficiency becomes large as the emitting material.

Specific examples of the substituents for the rings A³⁰¹ and A³⁰²forming the ligand of the formula (K) include halogen atoms such aschlorine, bromine, iodine, and fluorine, substituted or unsubstitutedalkyl groups such as a methyl group, ethyl group, propyl group, butylgroup, sec-butyl group, tert-butyl group, pentyl group, hexyl group,heptyl group, octyl group, stearyl group, and trichloromethyl group,substituted or unsubstituted aryl groups such as a phenyl group,naphthyl group, biphenyl group, anthranyl group, phenanthryl group,fluorenyl group, pyrenyl group, 3-methylphenyl group, 3-methoxyphenylgroup, 3-fluorophenyl group, 3-trichloromethylphenyl group,3-trifluoromethylphenyl group, and 3-nitrophenyl group, substituted orunsubstituted alkoxy groups such as a methoxy group, n-butoxy group,tert-butoxy group, trichloromethoxy group, trifluoroethoxy group,pentafluoropropoxy group, 2,2,3,3-tetrafluoropropoxy group,1,1,1,3,3,3-hexafluoro-2-propoxy group, and 6-(perfluoroethyl)hexyloxygroup, substituted or unsubstituted aryloxy groups such as a phenoxygroup, p-nitrophenoxy group, p-tert-butylphenoxy group, 3-fluorophenoxygroup, pentafluorophenyl group, and 3-trifluoromethylphenoxy group,substituted or unsubstituted alkylthio groups such as a methylthiogroup, ethylthio group, tert-butylthio group, hexylthio group, octylthiogroup, and trifluoromethylthio group, substituted or unsubstitutedarylthio groups such as a phenylthio group, p-nitrophenylthio group,p-tert-butylphenylthio group, 3-fluorophenylthio group,pentafluorophenylthio group, and 3-trifluoromethylphenylthio group, acyano group, a nitro group, an amino group, mono- or di-substitutedamino groups such as a methylamino group, diethylamino group, ethylaminogroup, diethylamino group, dipropylamino group, dibutylamino group, anddiphenylamino group, acylamino groups such as a bis(acetoxymethyl)aminogroup, bis(acetoxyethyl)amino group, bis(acetoxypropyl)amino group, andbis(acetoxybutyl)amino group, a hydroxyl group, a siloxy group, an acylgroup, substituted or unsubstituted carbamoyl groups such as a carbamoylgroup, methylcarbamoyl group, dimethylcarbamoyl group, ethylcarbamoylgroup, diethylcarbamoyl group, propylcarbamoyl group, butylcarbamoylgroup, and phenylcarbamoyl group, a carboxylic acid group, a sulfonicacid group, an imide group, cycloalkyl groups such as a cyclopentanegroup and cyclohexyl group, heterocyclic groups such as a pyridinylgroup, pyrazinyl group, pyrimidinyl group, pyridazinyl group, triazinylgroup, indolinyl group, quinolinyl group, acridinyl group, pyrrolidinylgroup, dioxanyl group, piperidinyl group, morpholidinyl group,piperazinyl group, carbazolyl group, furanyl group, thiophenyl group,oxazolyl group, oxadiazolyl group, benzoxazolyl group, thiazolyl group,thiadiazolyl group, benzothiazolyl group, triazolyl group, imidazolylgroup, and benzimidazolyl group. The above substituents may be bonded toform a further six-membered aryl ring or heterocyclic ring.

A preferred embodiment of the organic EL device is a device containing areducing dopant in an electron-transferring region or in an interfacialregion between a cathode and an organic layer. The reducing dopant isdefined as a substance which can reduce an electron-transferringcompound. Accordingly, various substances which have given reducingproperties can be used. For example, at least one substance can bepreferably used which is selected from the group consisting of alkalimetals, alkaline earth metals, rare earth metals, alkali metal oxides,alkali metal halides, alkaline earth metal oxides, alkaline earth metalhalides, rare earth metal oxides, rare earth metal halides, alkali metalcarbonates, alkaline earth metal carbonates, rare earth metalcarbonates, alkali metal organic complexes, alkaline earth metal organiccomplexes, and rare earth metal organic complexes.

More specific examples of the preferred reducing dopants include atleast one alkali metal selected from the group consisting of Na (workfunction: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16eV) and Cs (work function: 1.95 eV), and at least one alkaline earthmetal selected from the group consisting of Ca (work function: 2.9 eV),Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV).Metals having a work function of 2.9 eV or less are particularlypreferred. Among these, a more preferable reducing dopant is at leastone alkali metal selected from the group consisting of K, Rb and Cs.Even more preferable is Rb or Cs. Most preferable is Cs. These alkalimetals are particularly high in reducing ability. Thus, the addition ofa relatively small amount thereof to an electron-injecting zone improvesthe luminance of the organic EL device and make the lifetime thereoflong. As a reducing agent having a work function of 2.9 eV or less,combinations of two or more alkali metals are preferable, particularlycombinations including Cs, such as Cs and Na, Cs and K, Cs and Rb, orCs, Na and K are preferable. The combination containing Cs makes itpossible to exhibit the reducing ability efficiently. The luminance ofthe organic EL device can be improved and the lifetime thereof can bemade long by the addition thereof to its electron-injecting zone.

An electron-injecting layer made of an insulator or a semiconductor mayfurther be provided between a cathode and an organic layer. By formingthe electron-injecting layer, a current leakage can be effectivelyprevented and electron-injecting properties can be improved. If theelectron-injecting layer is an insulating thin film, more uniformed thinfilm can be formed whereby pixel defects such as a dark spot aredecreased.

As the insulator, at least one metal compound selected from the groupconsisting of alkali metal calcogenides, alkaline earth metalcalcogenides, halides of alkali metals and halides of alkaline earthmetals can be preferably used. When the electron-injecting layer isformed of the alkali metal calcogenide or the like, the injection ofelectrons can be preferably further improved. Specifically preferablealkali metal calcogenides include Li₂O, K₂O, Na₂S, Na₂Se and Na₂O andpreferable alkaline earth metal calcogenides include CaO, BaO, SrO, BeO,BaS and CaSe. Preferable halides of alkali metals include LiF, NaF, KF,CsF, LiCl, KCl and NaCl. Preferable halides of alkaline earth metalsinclude fluorides such as CaF₂, BaF₂, SrF₂, MgF₂ and BeF₂ and the otherhalides corresponding to the fluorides.

Semiconductors forming an electron-injecting layer include one orcombinations of two or more of oxides, nitrides, and oxidized nitridescontaining at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na,Cd, Mg, Si, Ta, Sb and Zn. An inorganic compound forming anelectron-injecting layer is preferably a microcrystalline or amorphousinsulating thin film.

For the cathode, the following may be used: an electrode substance madeof a metal, an alloy or an electroconductive compound, or a mixturethereof which has a small work function (for example, 4 eV or less).Specific examples of the electrode substance include sodium,sodium-potassium alloy, magnesium, lithium, cesium, magnesium/silveralloy, aluminum/aluminum oxide, Al/Li₂O, Al/LiO, Al/LiF,aluminum/lithium alloy, indium, and rare earth metals.

The cathode is formed from these electrode materials by vapordeposition, sputtering or the like.

In the case where emission from the emitting layer is outcoupled throughthe cathode, it is preferred to make the transmittance of the cathode tothe emission larger than 10%. The sheet resistance of the cathode ispreferably several hundreds Ω/□ or less, and the film thickness thereofis usually from 10 nm to 1 μm, preferably from 50 to 200 nm.

Generally, in the organic EL device, pixel defects based on leakage or ashort circuit are easily generated since an electric field is applied tothe super thin film. In order to prevent this, it is preferred to insertan insulating thin layer between the pair of electrodes.

Examples of the material used in the insulating layer include aluminumoxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide,magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride,aluminum nitride, titanium oxide, silicon oxide, germanium oxide,silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide, andvanadium oxide. A mixture or laminate thereof may be used.

As for the method for fabricating the organic EL device, it can befabricated by forming necessary layers sequentially from the anode usingthe materials and the method as mentioned above, and finally forming thecathode. The organic EL device can be fabricated in the order reverse tothe above, i.e., the order from the cathode to the anode.

An example of the fabrication of the organic EL device will be describedbelow which has a structure wherein the following are successivelyformed on a transparent substrate: anode/hole-injecting layer/emittinglayer/electron-injecting layer/cathode.

At first, a thin film formed of an anode material is formed on atransparent substrate by vapor deposition or sputtering to form ananode.

Next, a hole-injecting layer is formed on this anode. As describedabove, the hole-injecting layer can be formed by vacuum deposition, spincoating, casting, LB technique, or some other method. Vacuum depositionis preferred since a homogenous film is easily obtained and pinholes arenot easily generated. In the case where the hole-injecting layer isformed by vacuum deposition, conditions for the deposition varydepending upon a compound used (a material for the hole-injectinglayer), a desired structure of the hole-injecting layer, and others. Ingeneral, the conditions are preferably selected from the following:deposition source temperature of 50 to 450° C., vacuum degree of 10⁻⁷ to10⁻³ Torr, vapor deposition rate of 0.01 to 50 nm/second, and substratetemperature of −50 to 300° C.

Next, an emitting layer is formed on the hole-injecting layer. Theemitting layer can also be formed by making a luminescent material intoa thin film by vacuum vapor deposition, sputtering, spin coating,casting or some other method. Vacuum vapor deposition is preferred sincea homogenous film is easily obtained and pinholes are not easilygenerated. In the case where the emitting layer is formed by vacuumvapor deposition, conditions for the deposition, which vary depending ona compound used, can be generally selected from conditions similar tothose for the hole-injecting layer.

Next, an electron-injecting layer is formed on the emitting layer. Likethe hole-injecting layer and the emitting layer, the layer is preferablyformed by vacuum vapor deposition because a homogenous film is required.Conditions for the deposition can be selected from conditions similar tothose for the hole-injecting layer and the emitting layer.

Lastly, a cathode is stacked thereon to obtain an organic EL device. Thecathode can be formed by vapor deposition or sputtering. However, vaporvacuum deposition is preferred in order to protect underlying organiclayers from being damaged when the cathode film is formed.

For the organic EL device fabrication described above, it is preferredthat the formation from the anode to the cathode is continuously carriedout, using only one vacuuming operation.

The method for forming each of the layers in the organic EL device isnot particularly limited. An organic thin film layer containing thecompound of the invention can be formed by a known method such as vacuumvapor deposition, molecular beam epitaxy (MBE), or an applying coatingmethod using a solution in which the compound is dissolved in a solvent,such as dipping, spin coating, casting, bar coating, or roll coating.

EXAMPLES

The invention will be specifically explained with reference to examplesbelow.

Synthesis Example 1

Triphenylenyl trifluoromethane sulfonate (intermediate A) wassynthesized by the following reaction.

(A-1) Synthesis of 3-methoxy[1,1′:2′,1″]terphenyl

Under an argon atmosphere, 18.7 g of 3-bromoanisole, 23.8 g of2-biphenylboronic acid and 2.31 g oftetraxis(triphenylphosphine)palladium(0) were placed in a flask. 340 mLof dimethyl ether (DME) and 170 mL of a 2M aqueous sodium carbonatesolution were added to this flask, and the resultant was refluxed withstirring while heating for 8 hours. After cooling to room temperature,an aqueous phase was removed. An organic phase was washed with water andsaturated brine, and then dried with magnesium sulfate. After themagnesium sulfate was filtered out, the organic phase was concentrated.The resulting residue was purified by means of silica gel columnchromatography, whereby 23.4 g (yield: 90%) of intended3-methoxy[1,1′:2′,1″]terphenyl was obtained.

(A-2) Synthesis of 2-methoxytriphenylene

23.4 g of 3-methoxy[1,1′:2′,1″]terphenyl, 146 g of iron (III) chlorideand 200 mL of methylene chloride were placed in a flask, and stirred forone hour while deaerating with argon. The reaction solution wassubjected to filtration, followed by washing with an excessive amount ofacetone. The resulting solid was dissolved in heated toluene. Insolublesubstances were filtered out, followed by crystallization with cooling.The resulting crystal was collected by filtration to obtain 13.9 g(yield: 60%) of 2-methoxytriphenylene.

(A-3) Synthesis of 2-hydroxytriphenylene

Under an argon atmosphere, 13.9 g of 2-methoxytriphenylene was placed ina flask, and 300 mL of methylene chloride was added. The reactionsolution was cooled to −78° C., and 54 mL of a solution of 1M boronboron tribromide in methylene chloride was dropwise added thereto. Thereaction solution was stirred for 5 hours while increasing temperatureof the reaction solution to room temperature. 100 mL of water was addedto the reaction solution, followed by filtration. The resulting solidwas washed with water and methanol to obtain 12.5 g (yield: 95%) of2-hydroxytriphenylene.

(A-4) Synthesis of Intermediate A

Under an argon atmosphere, 12.5 g of 2-hydroxytriphenylene and 0.93 g of4-dimethylaminopiridine were placed in a flask, 200 mL of methylenechloride was added thereto and the reaction solution was cooled to −78°C. 8.22 g of 2,6-dimethylpiridine was added to the reaction solution andthen, 17.3 g of trifluoromethanesulfonic acid anhydride was dropwiseadded thereto. The reaction solution was stirred for 5 hours whileincreasing temperature of the reaction solution to room temperature. Thedeposited solid was collected by filtration, washed with water andmethanol and then dried to obtain 17.3 g (yield: 90%) of triphenylenyltrifluoromethanesulfonate.

Synthesis Example 2 Synthesis of 2-(3-buromophenyl)triphenylene(Intermediate B)

2-(3-bromophenyl)triphenylene (intermediate B) was synthesized from theintermediate A obtained in Synthesis Example 1 by the followingreaction.

(B-1) Synthesis of triphenylene-2-boronic Acid Pinacol Ester

Under an argon atmosphere, 37.6 g of triphenylenyltrifluoromethanesulfonate, 27.9 g of bis(pinacolato)diboron, 2.45 g of1,1′-bis(diphenylphosphino)ferrocene palladium (II) dichloridedichloromethane complex, 1.66 g of 1,1′-bis(diphenylphosphino)ferroceneand 29.4 g of potassium acetate were placed in a flask. 600 mL ofanhydrous dioxane was added thereto, and the resultant was refluxed withstirring while heating for 8 hours. After cooling to room temperature,300 mL of water was added to the reaction solution, followed byextraction with toluene. An aqueous phase was removed, and an organicphase was washed with water and saturated brine, and then dried withmagnesium sulfate. Magnesium sulfate was removed and the solvent wasdistilled under reduced pressure. The resulting residue was purified bymeans of silica gel column chromatography, whereby 14.1 g (yield: 40%)of triphenylene-2-boronic acid piconal ester was obtained.

(B-2) Synthesis of Intermediate B

Under an argon atmosphere, 3.54 g of triphenylene-2-boronic acid piconalester, 2.83 g of 3-bromoiodebenzene, 0.231 g oftetrakis(triphenylphosphine)palladium (0), 40 mL of toluene and 20 mL ofa 2M sodium carbonate aqueous solution were placed in a flask, andrefluxed with stirring for 8 hours. After cooling to room temperature,the reaction solution was extracted with toluene. An aqueous phase wasremoved, and an organic phase was washed with water and saturated brinesequentially, and then dried with magnesium sulfate. Magnesium sulfatewas filtered out, and then the organic phase was concentrated. Theresulting residue was purified by means of a silica gel columnchromatography to obtain 3.64 g (95%) of an intermediate B.

Synthesis Example 3 Synthesis of 2-(4-bromophenyl)triphenylene(Intermediate C)

In (B-2) above, 2-(4-bromophenyl)triphenylene (intermediate C) wassynthesized in the same manner as in Synthesis Example 2 except that4-bromoiodobenzene was used in place of 3-bromoiodobenzen.

Synthesis Example 4 Synthesis of 2-methoxytriphenylene (Intermediate D)

2-methoxytriphenylene (intermediate D) was synthesized by the followingreaction.

Under an argon atmosphere, 3.87 mL of 2-iodobiphenyl, 11.52 mL oftrifluoromethanesulfonate 4-methoxy-2-(trimethylsilyl)phenyl, 0.63 g ofbis(dibenzylideneacetone)palladium, 0.33 g of tri(o-tolyl)phosphine, 270mL of toluene and 30 mL of acetonitrile were placed in a flask andrefluxed with heat while stirring at 110° C. for 6 hours. Aftercompletion of the reaction, water was added to the reaction solution. Anaqueous phase was removed, and then an organic phase was washed withsaturated brine. The organic phase was dried with magnesium sulfate andthen concentrated. The resulting residue was purified by means of asilica gel column chromatography to obtain 1.34 g (yield: 23%) of2-methoxytriphenylene (intermediate D) as a white crystal.

[Synthesis of Fused Aromatic Derivatives]

Example 1

The following compound 1 was synthesized from intermediate A by thefollowing reaction.

Under an argon atmosphere, 3.76 g of intermediate A obtained inSynthesis Example 1, 4.18 g of 10-(2-naphthyl)anthracene-9-boronic acidwhich was synthesized by a known method, 0.231 g oftetrakis(triphenylphosphine)palladium (0), 40 mL of toluene and 20 mL ofa 2M sodium carbonate aqueous solution were placed in a flask andrefluxed with stirring for 8 hours. After cooling to room temperature,the reaction solution was extracted with toluene. An aqueous phase wasremoved, and an organic phase was washed with water and saturated brinesequentially and dried with magnesium sulfate. Magnesium sulfonate wasfiltered out, and then the organic phase was concentrated. The resultingresidue was purified by means of a silica gel column chromatography toobtain 4.35 g of a pale yellow crystal.

As a result of mass spectrum analysis, m/z=530, and it was confirmedthat the product of the synthesis was Compound 1 (molecular weight:530.20).

Example 2

The following compound 2 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except that10-[4-(1-naphthyl)phenyl]anthracene-9-boronic acid which was synthesizedby a known method was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=606, and it was confirmedthat the product of the synthesis was Compound 2 (molecular weight:606.23).

Example 3

The following compound 3 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except that10-[4-(2-naphthyl)phenyl]anthracene-9-boronic acid which was synthesizedby a known method was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=606 and it was confirmed thatthe product of the synthesis was Compound 3 (molecular weight: 606.23).

Example 4

The following compound 4 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except that10-[3-(2-naphthyl)phenyl]anthracene-9-boronic acid which was synthesizedby a known method was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=606, and it was confirmedthat the product of the synthesis was Compound 4 (molecular weight:606.23).

Example 5

The following compound 5 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except that10-[3-(1-naphthyl)phenyl]anthracene-9-boronic acid which was synthesizedby a known method was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=606, and it was confirmedthat the product of the synthesis was Compound 5 (molecular weight:606.23).

Example 6

The following compound 6 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except thatIntermediate B which was synthesized in Synthesis Example 2 was used inplace of triphenylenyl trifluoromethanesulfonate (intermediate A).

As a result of mass spectrum analysis, m/z=606, and it was confirmedthat the product of the synthesis was Compound 6 (molecular weight:606.23).

Example 7

The following compound 7 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 6 except that10-[4-(1-naphthyl)phenyl]anthracene-9-boronic acid was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=682, and it was confirmedthat the product of the synthesis was Compound 7 (molecular weight:682.27).

Example 8

The following compound 8 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 6 except that10-[3-(2-naphghyl)phenyl]anthracene-9-boronic acid was used in place of10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=682, and it was confirmedthat the product of the synthesis was Compound 8 (molecular weight:682.27).

Example 9

The following compound 9 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in Example 1 except thatIntermediate C synthesized in Synthesis Example 3 was used in place ofIntermediate A, and 10-[3-(2-naphthyl)phenyl]anthracene-9-boronic acidwas used in place of 10-(2-naphthyl)anthracene-9-boronic acid.

As a result of mass spectrum analysis, m/z=682, and it was confirmedthat the product of the synthesis was Compound 9 (molecular weight:682.27).

[Fabrication of Organic EL Device]

Example 10

A glass substrate of 25 mm by 75 mm by 1.1 mm thick with an ITOtransparent electrode (anode) (GEOMATEC CO., LTD.) was subjected toultrasonic cleaning with isopropyl alcohol for 5 minutes, and thencleaned with ultraviolet rays and ozone for 30 minutes. The cleanedglass substrate with transparent electrode lines was mounted in asubstrate holder of a vacuum vapor deposition apparatus. First, a 60nm-thick film of the following compound A-1 was formed on the surfacewhere the transparent electrode lines were formed so as to cover thetransparent electrode.

Subsequently to the film formation of A-1 film, a 20 nm-thick film ofthe following compound A-2 was formed on the A-1 film.

A 40 nm-thick film was formed on the A-2 film using Compound 1 of theinvention and a styrylamine derivative D-1 in a film thickness ratio of40:2, to obtain a blue-light emitting layer.

On this film, a 20 nm-thick film was formed as an electron transportinglayer using the following compound Alq by deposition, followed byformation of a 1 nm-thick LiF film. A 150 nm-thick metal Al film wasformed on the LiF film by deposition to form a metal cathode, whereby anorganic EL device was obtained.

Examples 11 to 18

As shown in Table 1, organic EL devices were fabricated in the samemanner as in Example 10 except that Compounds 2 to 9 were used in placeof Compound 1.

Comparative Example 1

An organic EL device was fabricated in the same manner as in Example 10except that the following compound (B) was used in place of Compound 1.

Comparative Example 2

An organic EL device was fabricated in the same manner as in Example 10except that the following compound (C) was used in place of Compound 1.

For the organic EL devices fabricated in each example above, deviceperformance under driven at 10 mA/cm² and the half life (time) at theinitial luminance of 1000 cd/m² were measured. The results are shown inTable 1.

TABLE 1 Luminous Host Dopant efficiency (cd/A) Half life Ex. 10 Compound1 D-1 6.5 8000 Ex. 11 Compound 2 D-1 6.5 8000 Ex. 12 Compound 3 D-1 6.58000 Ex. 13 Compound 4 D-1 6.5 8000 Ex. 14 Compound 5 D-1 6.5 8000 Ex.15 Compound 6 D-1 6.5 8000 Ex. 16 Compound 7 D-1 6.7 7000 Ex. 17Compound 8 D-1 6.7 7000 Ex. 18 Compound 9 D-1 6.7 7000 Comp. Ex. 1Compound (B) D-1 6.0 4000 Comp. Ex. 2 Compound (C) D-1 4.2 2000

Example 19 (Synthesis of Compound 10)

The following compound 10 was synthesized by the following reaction.

(1) Synthesis of 2-(2-anthryl)triphenylene

Under an argon atmosphere, 7.79 g of triphenylene-2-boronic acid piconalester, 5.14 g of 2-bromoanthracene, 0.462 g oftetrakis(triphenylphosphine)palladium (0), 30 mL of 1,2-dimethoxyethaneand 15 mL of a 2M sodium carbonate aqueous solution were placed in aflask, and refluxed with stirring for 8 hours. After cooling to roomtemperature, deposited crystals were collected by filtration. Theresulting solid was subjected to repeated recrystallization withtoluene-hexane and washing to obtain 6.07 g (yield: 75%) of2-(2-anthryl)triphenylene.

(2) Synthesis of 2-(9,10-dibromoanthracene-2-yl)triphenylene

6.07 g of 2-(2-anthryl)triphenylene was dissolved with heat in 100 mL ofN,N-dimethylformamide. A solution of 5.87 g of N-bromosuccinimide in 10mL of N,N-dimethylformamide was added thereto, and the reaction solutionwas heated with stirring at 60° C. for 6 hours. After cooling to roomtemperature, the reaction solution was poured into 1 L of water. Theresulting solid was washed with methanol, water and methanolsequentially. Then, recrystallization with toluene-hexane and washingwere repeated to obtain 6.75 g (yield: 80%) of2-(9,10-dibromoanthracene-2-yl)triphenylene.

(3) Synthesis of Compound 10

Under an argon atmosphere, 5.62 g of2-(9,10-dibromoanthracene-2-yl)triphenylene, 3.78 g of2-naphthaleneboronic acid, 0.462 g oftetrakis(triphenylphosphin)palladium (0), 40 mL of toluene and 20 mL ofa 2M sodium carbonate aqueous solution were placed in a flask andrefluxed with stirring for 8 hours. After cooling to room temperature,deposited crystals were collected by filtration. The resulting crystalswere washed with methanol, water and methanol, and then recrystallizedwith toluene to obtain 4.26 g of yellow crystals. As a result of massspectrum analysis, m/e=656 for the molecular weight of 656.25 of theintended product, and it was confirmed that the compound was theintended product.

Example 20 (Synthesis of Compound 11)

The following compound 11 was synthesized by the following reaction.

Synthesis was conducted in the same manner as in the synthesis ofCompound 10 except that 3-(1-naphthyl)phenylboronic acid which wassynthesized by a known method was used in place of 2-naphthareneboronicacid. As a result of mass spectrum analysis, m/e=808 for the molecularweight of the intended product of 808.31, and it was confirmed that thecompound was the intended product.

[Fabrication of Organic EL Device]

Example 21

An organic EL device was fabricated in the same manner as in Example 10except that a 40 nm-thick film was formed as a blue-color emitting layerusing Compound 10 of the invention and Compound D-2 having the followingstructure in a film thickness ratio of 40:2.

Example 22

An organic EL device was fabricated in the same manner as in Example 10except that a 40 nm-thick film was formed as a blue-color emitting layerusing Compound 11 of the invention and Compound D-2 in a film thicknessratio of 40:2.

Example 23

An organic EL device was fabricated in the same manner as in Example 21except that Compound D-3 having the following structure was used inplace of Compound D-2.

Example 24

An organic EL device was fabricated in the same manner as in Example 22except that Compound D-3 was used in place of Compound D-2.

Comparative Example 3

An organic EL device was fabricated in the same manner as in ComparativeExample 1 except that Compound D-2 was used in place of Compound D-1.

For the organic EL devices fabricated in each example above, deviceperformance under driven at 10 mA/cm² and the half life (time) at theinitial luminance of 1000 cd/m² were measured. The results are shown inTable 2.

TABLE 2 Volt- Luminous Dop- age efficiency Emission Half Host ant (V)(cd/A) color life Ex. 21 Compound 10 D-2 6.4 22 Green 30000 Ex. 22Compound 11 D-2 6.5 22 Green 30000 Ex. 23 Compound 10 D-3 6.5 21 Green50000 Ex. 24 Compound 11 D-3 6.5 21 Green 50000 Comp. Compound (B) D-27.0 17 Green 10000 Ex. 3

INDUSTRIAL APPLICABILITY

The fused aromatic ring derivative of the invention is preferable as amaterial for an organic EL device, in particular, as an emittingmaterial.

The organic EL device of the invention can be suitably used as a lightsource such as a planar emitting body and backlight of a display, adisplay part of a portable phone, a PDA, a car navigator, or aninstrument panel of an automobile, an illuminator, and the like.

The documents described in the specification are incorporated herein byreference in its entirety.

The invention claimed is:
 1. A fused aromatic derivative shown by thefollowing formula (1-1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, p is an integer of 1 to 8, and q is an integer of 1 to 11,when p or q is 2 or more, R_(a)s or R_(b)s may be independently the sameor different, and Ar₁′ is a substituted or unsubstituted dibenzofuranyl,provided that substituents of Ar₁′ and R_(a) and R_(b) contain no aminogroup.
 2. A material for an organic electroluminescence devicecomprising the fused aromatic derivative according to claim
 1. 3. Thematerial for an organic electroluminescence derivative according toclaim 2, which is an emitting material.
 4. An organicelectroluminescence device comprising: an anode, a cathode, and one ormore organic thin film layers comprising an emitting layer between theanode and the cathode, wherein at least one of the organic thin filmlayers comprises the fused aromatic derivative according to claim
 1. 5.The organic electroluminescence device according to claim 4, wherein theemitting layer comprises the fused aromatic derivative.
 6. The organicelectroluminescence device according to claim 5, wherein the emittinglayer comprises the fused aromatic derivative as a host material.
 7. Theorganic electroluminescence device according to claim 4, wherein theemitting layer further comprises at least one of a fluorescent dopantand a phosphorescent dopant.
 8. The organic electroluminescence deviceaccording to claim 7, wherein the fluorescent dopant is an arylaminecompound.
 9. The organic electroluminescence device according to claim7, wherein the fluorescent dopant is a styrylamine compound.
 10. Thefused aromatic derivative according to claim 1, which is shown by thefollowing formula (1-1a):

wherein R_(a) and Ar₁′ are the same as in the formula (1-1).
 11. Thefused aromatic derivative according to claim 1, wherein Ar₁′ is a1-dibenzofuranyl group, 2-dibenzofuranyl group, 3-dibenzofuranyl group,or 4-dibenzofuranyl group.
 12. The fused aromatic derivative accordingto claim 1, wherein R_(a) and R_(b) are a hydrogen atom.
 13. The fusedaromatic derivative according to claim 1, wherein the substituted orunsubstituted dibenzofuranyl group is bonded to anthracene at 2ndposition, 3rd position or 1st position of dibenzofuranyl ordibenzothiophenyl.
 14. The fused aromatic derivative according to claim13, wherein Ar₁′ is a 2-dibenzofuranyl group, a 3-dibenzofuranyl group,or a 1-dibenzofuranyl group.